This view of the twilight sky and Martian horizon taken by NASA's Curiosity Mars rover includes Earth as the brightest point of light in the night sky. Earth is a little left of center in the image, and our moon is just below Earth.

This frame from an animation from NASA's Mars rover Curiosity shows the rover drilling into rock target 'Cumberland.' The drilling was performed during the 279th Martian day, or sol, of the Curiosity's work on Mars (May 19, 2013).

This image from the Mars Hand Lens Imager on NASA's Mars rover Curiosity shows the patch of rock cleaned by the first use of the rover's Dust Removal Tool (DRT). The tool is a motorized, wire-bristle brush on the turret at the end of the rover's arm.

The two bodies in this portion of an evening-sky view by NASA's Mars rover Curiosity are Earth and Earth's moon. The rover's Mast Camera (Mastcam) imaged them in the twilight sky of Curiosity's 529th Martian day, or sol (Jan. 31, 2014).

This mosaic of images from the Mastcam onboard NASA's Mars rover Curiosity shows Mount Sharp in raw color. Raw color shows the scene's colors as they would look in a typical smart-phone camera photo, before any adjustment.

This mosaic of images from the Mast Camera (Mastcam) on NASA's Mars rover Curiosity shows Mount Sharp in a white-balanced color adjustment that makes the sky look overly blue but shows the terrain as if under Earth-like lighting.

This false-color map shows the area within Gale Crater on Mars, where NASA's Curiosity rover landed on Aug. 5, 2012 PDT (Aug. 6, 2012 EDT) and the location where Curiosity collected its first drilled sample at the 'John Klein' rock.

A sampling pit exposing clay-bearing lake sediments, deposited in a basaltic basin in southern Australia -- a modern terrestrial analog to the 'Yellowknife Bay' area that NASA's Curiosity rover is exploring.

These images, made from data obtained by Curiosity's CheMin, show the patterns obtained from a drift of windblown dust and sand called 'Rocknest' and from a powdered rock sample drilled from the 'John Klein' bedrock.

This frame from an animation of NASA's Curiosity rover shows the complicated suite of operations involved in conducting the rover's first rock sample drilling on Mars and transferring the sample to the rover's scoop for inspection.

This frame from a video clip shows moments during a demonstration of drilling into a rock at NASA's JPL, Pasadena, Calif., with a test double of the Mars rover Curiosity. The drill combines hammering and rotation motions of the bit.

The development of the Mars rover Curiosity's capabilities for drilling into a rock on Mars required years of development work. Seen here are some of the rocks used in bit development testing and lifespan testing at JPL in 2007.

This figure shows the location of CHIMRA on the turret of NASA's Curiosity rover, together with a cutaway view of the device. CHIMRA processes samples from the rover's scoop or drill and delivers them to science instruments.

This image from the Mars Hand Lens Imager (MAHLI) on NASA's Mars rover Curiosity shows details of rock texture and color in an area where the rover's Dust Removal Tool (DRT) brushed away dust that was on the rock.

From a position in the shallow 'Yellowknife Bay' depression, NASA's Mars rover Curiosity used its right Mast Camera (Mastcam) to take the telephoto images combined into this panorama of geological diversity.

A day after NASA's Mars rover Curiosity drilled the first sample-collection hole into a rock on Mars, the rover's Chemistry and Camera (ChemCam) instrument shot laser pulses into the fresh rock powder that the drilling generated.

NASA's Mars rover Curiosity used its Mast Camera (Mastcam) to take the images combined into this mosaic of the drill area, called 'John Klein,' where the rover ultimately performed its first sample drilling.